Answer: TME includes cancer-associated fibroblasts, tumour-associated macrophages, regulatory T cells, and blood vessels; TAMs often promote (not fight) cancer, and TME manipulation is a target for immunotherapy.
- A Cancer cells are sometimes thought to grow in isolation from surrounding cells, with little cancer-associated fibroblast, macrophage, or regulatory T cell influence on tumour growth and spread in the majority of cases studied
- B TME includes cancer-associated fibroblasts, tumour-associated macrophages, regulatory T cells, and blood vessels; TAMs often promote (not fight) cancer, and TME manipulation is a target for immunotherapy
- C The immune system is sometimes thought to usually eliminate cancer, despite immune editing allowing tumour variants that evade detection to survive, persist, and eventually escape immune control as widely reported
- D The TME is sometimes thought to have no role in cancer treatment, when in fact manipulating macrophages, fibroblasts, and regulatory T cells is now an active target for cancer immunotherapy in standard practice
Correct answer: B. TME includes cancer-associated fibroblasts, tumour-associated macrophages, regulatory T cells, and blood vessels; TAMs often promote (not fight) cancer, and TME manipulation is a target for immunotherapy
Explanation: TME is the non-cancerous cellular and molecular environment surrounding tumour cells. TAMs (M2 polarized): secrete TGF-beta, IL-10, VEGF, MMPs - promote invasion, suppress immunity. CAFs: produce TGF-beta, SDF-1, remodel ECM, promote invasion. Tregs: suppress CTL anti-tumour response. Tumour angiogenesis (VEGF-driven): provides nutrients. Immunotherapy targets TME: anti-PD-1/PD-L1 (pembrolizumab, nivolumab) block T cell exhaustion to restore anti-tumour immunity.
The Plasmodium parasite needs both hosts: the female Anopheles mosquito injects sporozoites while biting (infecting the human liver and RBCs, causing the malaria fever cycle), then picks up gametocytes from an infected person's blood, completing the parasite's sexual stage inside the mosquito.
Concept context
Pathogens, infectious diseases, non-infectious diseases, drugs, cancer, and public health. High NEET importance.